In terms of overall gaming performance, the AMD Phenom II X3 715 is marginally better than the AMD APU A6-9550 4-Core 3.8GHz when it comes to running the latest games. This also means it will be less likely to bottleneck more powerful GPUs, allowing them to achieve more of their gaming performance potential.

The APU A6-9550 4-Core was released over three years more recently than the Phenom II X3, and so the APU A6-9550 4-Core is likely to have far better levels of support, and will be much more optimized and ultimately superior to the Phenom II X3 when running the latest games.

The Phenom II X3 has 1 more core than the APU A6-9550 4-Core. However, while the Phenom II X3 will probably perform better than the APU A6-9550 4-Core, both CPUs are likely to struggle with the latest games, and will almost certainly bottleneck high-end graphics cards. This should not affect games that are a few years old, and even the latest games should at least be playable on very low settings, as only recently have game developers begun to harness the power of multiple cores.

The Phenom II X3 has 1 more threads than the APU A6-9550 4-Core. Both CPUs have one thread per physical core.

Multiple threads are useful for improving the performance of multi-threaded applications. Additional cores and their accompanying thread will always be beneficial for multi-threaded applications. Hyperthreading will be beneficial for applications optimized for it, but it may slow others down. For games, the number of threads is largely irrelevant, as long as you have at least 2 cores (preferably 4), and hyperthreading can sometimes even hit performance.

More important for gaming than the number of cores and threads is the clock rate. Problematically, unless the two CPUs are from the same family, this can only serve as a general guide and nothing like an exact comparison, because the clock cycles per instruction (CPI) will vary so much.

The APU A6-9550 4-Core and Phenom II X3 are not from the same family of CPUs, so their clock speeds are by no means directly comparable. Bear in mind, then, that while the APU A6-9550 4-Core has a 1 GHz faster frequency, this is not always an indicator that it will be superior in performance, despite frequency being crucial when trying to avoid GPU bottlenecking. In this case, however, the difference is probably a good indicator that the Phenom II X3 is superior.

Aside from the clock rate, the next-most important CPU features for PC game performance are L2 and L3 cache size. Faster than RAM, the more cache available, the more data that can be stored for lightning-fast retrieval. L1 Cache is not usually an issue anymore for gaming, with most high-end CPUs eking out about the same L1 performance, and L2 is more important than L3 - but L3 is still important if you want to reach the highest levels of performance. Bear in mind that although it is better to have a larger cache, the larger it is, the higher the latency, so a balance has to be struck.

The Phenom II X3 has a 512 KB bigger L2 cache than the APU A6-9550 4-Core, and although the APU A6-9550 4-Core does not appear to have an L3 cache, its larger L2 cache means that it wins out in this area.

The maximum Thermal Design Power is the power in Watts that the CPU will consume in the worst case scenario. The lithography is the semiconductor manufacturing technology being used to create the CPU - the smaller this is, the more transistors that can be fit into the CPU, and the closer the connections. For both the lithography and the TDP, it is the lower the better, because a lower number means a lower amount of power is necessary to run the CPU, and consequently a lower amount of heat is produced.

The APU A6-9550 4-Core has a 30 Watt lower Maximum TDP than the Phenom II X3, and was created with a 17 nm smaller manufacturing technology. What this means is the APU A6-9550 4-Core will consume significantly less power and consequently produce less heat, enabling more prolonged computational tasks with fewer adverse effects. This will lower your yearly electricity bill significantly, as well as prevent you from having to invest in extra cooling mechanisms (unless you overclock).